Friends is an important piece of pop culture history. The sitcom ran for 10 seasons spanning a decade, and featured an ensemble cast of six friends – Rachel Green (Jennifer Aniston), Monica Geller (Courteney Cox), Phoebe Buffay (Lisa Kudrow), Joey Tribbiani (Matt LeBlanc), Chandler  Bing (Matthew Perry), and Ross Geller (David Schwimmer), living in New York and navigating life as young singles.

RELATED: Friends: 10 Jokes That Have Already Aged Poorly

Eventually, some of them got together with one another, while others went through dating many other people who came and went into their lives. There were also career changes and other trials and tribulations. But they always stayed close, often meeting at their apartments or the local Central Perk coffee shop. Throughout the series, while there were lots of plotlines viewers totally saw coming, there were some interesting twists as well. Some were good for the story, others not so much. Here are some of the biggest twists.

Phoebe Discovers Who Her Biological Mother Is

Providing some interesting backstory into Phoebe’s life, she finds out that Phoebe Abbot, who she thought was a friend of her biological parents, is actually her biological mother.

Phoebe (senior) ends up being a great source of advice for Phoebe (junior), helping her make the tough decision to be a surrogate for her brother and his wife. She knows, after all, how important having a child is after the difficult decision she made to give hers up.

Chandler Kissed Rachel and Ross Kissed Monica in 1987

While we always knew Ross had a secret crush on Rachel even way back when they were teenagers and she was friends with Monica, a twist came when they realized that Chandler actually once kissed Rachel in 1987.

Not only that, but Ross kissed Monica by mistake, meaning she shared her first kiss ever with her own brother (ew!), a discovery she was horrified to make. Ross was equally horrified to find out that not only did Chandler lock lips with the woman he loved, but he did so at the college party that Ross thought, up until this point, was the place of his first kiss with Rachel.

David Moves to Minsk

David the Scientist Guy was a perfect match for Phoebe, so viewers really hoped they would end up together. But then in a surprise twist, he gets a job offer in Minsk, and has to choose his career over love.

RELATED: Friends: 10 Most Underrated Supporting Characters

He’d return every now and then, and there were clearly still feelings there between them, even while Phoebe was dating Mike. But in the end, it was Mike who captured her heart and she finally let David go. Not without a fight, however, from the scholarly man who was devastated to have finally ended his on-again, off-again relationship with Phoebe for good.

Ross Says Rachel’s Name At His Wedding…to Emily

Viewers thought all hope was lost between Ross and Rachel when Ross stood at the altar with Emily, ready to say their vows and become husband and wife. That is until the big twist: instead of saying Emily’s name, Ross looked his soon-to-be-wife in the eyes and called her Rachel!

It was a big twist that was very unfortunate for Emily, but proved that Ross still loved Rachel, even though he didn’t know at the time that she loved him, too. Not surprisingly, when Emily gave Ross an ultimatum ordering that he never see Rachel again, she became his second ex-wife.

Phoebe Rejects Mike’s Proposal

Viewers all thought Mike could finally be “the one” for Phoebe, until he revealed that he never wanted to get married. But then he threw a curveball and showed up to propose, just as David, “the one that got away” who had returned once again, was about to do the same. Phoebe then threw her own curveball and rejected Mike’s proposal.

It all worked out in the end, and Mike really was the one. They ended up getting their happily ever after, marrying in a simple, snowy ceremony outside of Central Perk.

Ross and Rachel Get Married in Vegas

Ross and Rachel get drunk and get married in Vegas in Friends

While viewers always thought Ross and Rachel would end up together, no-one saw a quickie wedding in Vegas happening. But that’s exactly what happened when they both got intoxicated.

RELATED: 10 Actors Who Got Big After Appearing On Friends

In another twist related to this one, while Ross told Rachel he annulled the wedding once they sobered up and realized what they had done in their drunken stupors, he secretly didn’t. So, they were actually married all along!

Rachel Gets Off the Plane

Rachel returns to Ross in Friends

Of course she was going to get off the plane. Or was she? While it was expected, viewers still weren’t sure if the series would provide a happy ending or not. So when Rachel got off the plane, choosing to stay with Ross instead of starting a new job in Paris, it was a sweet ending.

Viewers were left wondering if it was all over when a dejected Ross returned home from the airport. But then Rachel opened that door to his apartment to greet him and reveal that she never got on in the first place, unable to go through with it.

Rachel Finds Out She’s Pregnant

It was a beautiful twist when Rachel realized she was pregnant, and Ross was the father! She discovered the information right before Monica and Chandler’s wedding, and Phoebe finds the pregnancy test.

It might not have been a total twist that Ross was the father – it would have been totally awkward if it was anyone else, even though Ross and Rachel weren’t dating at the time. But when Ross claims the sweater that Joey realizes the mysterious father left in their apartment, the others all realize what happened and shock sets in.

Monica Tries to Propose to Chandler

Monica and Chandler in Friends

Viewers always knew Monica and Chandler would eventually get married. But what a surprise when it was Monica who got down on one knee to propose to him. Chandler thought he might have lost Monica forever, when she ended up seeing her old love Richard and Chandler tried to play it off as though he didn’t want to get married.

RELATED: Friends: Chandler Bing's 10 Best One-Liners

But she knew him better than that, and they were made for each other. So, when Chandler showed up at the apartment ready to confess that he did indeed want to get married, she had already set up candles and was waiting to propose to him instead. He took over, though, and finally got the job done.

Rachel and Joey Get Together

Not only the biggest twist of the series, but also the most bizarre: Joey and Rachel somehow get together and begin a relationship. He falls for her, she eventually realizes she has feelings for him too, and they date during the final season. The chemistry was lacking, and it’s a good thing they realized they were better off as friends.

This is a twist we wish hadn’t happened, as it hurt the series right before it was about to end. Especially since we knew Rachel simply had to end up with Ross. So, why throw this odd pairing into the mix when they had been such great friends for years? When Joey goes into Rachel’s hotel room in Barbados to seal the deal, it was just awkward. Viewers felt like a brother and sister were about to hook up. This is one twist the series could have done without.

NEXT: Other Places We've Seen The Stars Of Friends